Sanitary rubber sheet



June 20, 1944. J, H. JOHNSQN 2,351,767

SANITARY- RUBBER 'SHEET A Filed Jan. 16, 1941 l f Patented June 20,l 1944 ,UNITED STATES PATENT OFFICE 2,351,767 SANITARY RUBBER SHEET John H. Johnson, Toronto, Ontario, Canada.

v Application January 16,l 1941, Serial No. 374,677

2 Claims.

Thisinvention relates to improvements in the manufacture of rubber sheets particularly those used in hospitals but which are applicable for use in many other ways, and the principalobjects of the present invention are to provide a sheet which will 4effectively resist the deterioratunderneath the same and topress out any ridges or inequalities in the surface of the underside which is in contact with the smooth enamelled face. t I

Following the careful rolling of the sheet theA edges thereof are turned inwardly and folded i'ngelect of acids andwhich will be capable of being thoroughly sterilized and is sanitary in every respect.

A still further object is to produce a sheet which will not slip or creep on a mattress when placed upon a bed and which further will permit the free placement and adjustment of the ordinary linen or cotton sheets thereover.

The principal features of the invention consist.

in the novel manner lof fabricating the' sheet whereby the fabric reinforcement is completely sealedV within al rubber coating so that access of acids and other destructive fluids will be prevented from destroying the fabric reinforcement.

A further important feature consists'in pro. ducting a sheet with an extremely smooth face on one side anda definitely uniformly roughened face, on the other side.

Further important features consist in the novel steps in the method of producing a sheet as hereinafter described and claimed.

In the accompanying drawing Figure 1 is a perspective view showing theA manner of assembling the several elements that` v the sheet.

Figure 4 is a perspective view showing the manner offorminga uniformly -roughened surface on the back of the sheet. 4-

Figure 5 isan enlarged sectional detail of'one of the edges of the completed sheet 'showing the sealing of the edge thereof.

'v In the 'manufacture of the rubber sheets herein described it is found desirable to coat the reinforcing fabric sheet I by spreading thereon a-thin coating of a rubber solution of a suitable consistency. This coated sheet is then placed upon a thin rubber sheet 2 and a rubber sheet 3 is then -placed thereover land the whole is suitably calendered.

The calendered sheet is then laid upon an.

enamelled metal plate 4 and the composite sheet is then carefully rolled to remove all air from down tightly as illustrated in Figure 3 and after the edges 5 have been inturned, thin rubber strips 6 are laid over the edges of the inturned portions so as to completely overlie and cover the exposed edges of the vfabric reinforcement l. After these covering strips 6 have been placed 'in position a sheet of coarse woven fabric l is laid over the previously completed sheet and .the entire sheet is Ithenplaced in a press along tion on lthe surface' which will present a rough -friction surface which will prevent the completed sheet from slipping whenplaced upon a mattress.

After pressure has been applied -the coarse textile sheet is stripped from the lrubber sheet t which still adheres to the enamelled plate and the enamelled 4plate and rubber sheet pressed thereto is placed with others in a vulcanizing chamber wherelt is subjected to the required temperature and pressure to vulcanize the entire mass, and the top and bottom covering sheets with-the`ir infoldedV edges and overlaid sealing strips are all securelyvulcanized and the completed; sheetis thus thoroughly sealed against `ingress of moisture at any portion contacting with the fibrous reinforcement.

' Further, the vulcanizing of the sheet in direct contact withl the extremely smooth enamelled surface of the metal plate provides one surface of the rubber sheet with a smooth shiny surface which will offer the leastl possible resistance to slippage and a rubber sheet is produced which has a rough opposite surface adapted when placed downwardly against a mattress 'to prevent the sheet from slipping on the mat-v tress. Atthe .same time the composite sheet will present a smooth topside which wil-l permit v cotton or linen sheets to be pulled thereover with ease and there will be no fabric in the rubber sheet exposed to absorb-acids or to become contaminated with germs. Consequently the sheet can be thoroughly sterilized lby immersion in sterilizing solutions Lor by heat treatment as may be desired.

I claim as my invention is; t 1. A sanitary rubber sheet'| comprising a sheet of textile material having a thin sheet of rubber the textile fabric against the ingress of moisture. A

2. A sanitary rubber sheet comprising a sheet o 2 t g asume? of textile material having a thin sheet of rubber covering each face thereof, said composite sheet having its edges folded inwardly to form a thick ened frictional margin, the inner extremities o! the turned-over edges being overlaid with a sealing rubber strip to protect the textile fabric against 4the ingress of' moisture or germs, one tace of the fabricated sheet being formed with a -roughened surface similar to that voi a coarse l textile fabric, the other face presenting a smooth i shiny surface.

JOHN H. JOHNSON. 

